The primary goal of the proposed project is to determine, via a collaborative multicenter trial, whether interventions can: a) prevent persons with impaired glucose tolerance (IGT) or a history of gestational diabetes mellitus (GDM) from developing non-insulin-dependent diabetes mellitus (NIDDM); and b) prevent the worsening of glucose tolerance in people with newly diagnosed NIDDM. Because of the ethnic diversity of the study population, a secondary goal is to design the interventions to be sensitive to varying social, ethnic, and cultural values. With the use of the Regenstrief Medical Record System, we have identified three potential high risk populations: a) 6721 persons without a prior history of diabetes with random blood glucose values of 108-160 mg/dl and concomitant risk factors for NIDDM, of whom 54% are African American, b) 3688 patients with NlDDM in whom we will contact their first degree relatives, and c) between 530-600 women with a history of GDM projected to be available by enrollment, 34% of whom are African American. This population will serve as the primary target for our screening and recruitment efforts. Recruitment will be facilitated by use of social marketing techniques designed to assess in the target population, which is greater than 50% African American current behavioral patterns, perceived barriers, and health beliefs relevant to the health promotion goals of the project. Individuals meeting enrollment criteria will be randomized to one of the following four interventions: 1) non-intervention control, 2) diet- exercise-behavior modification (DEB), 3) pharmacologic therapy (PT), or 4) a combination of both DEB and PT. A unique feature of the nutrition component will be the use of specially trained lay persons termed "Community Health Educators", who are members of the same communities' as program participants, and will deliver the program in the subject's home. The exercise component of the proposed intervention is also designed to maximize long-term participation by establishing personalized exercise programs, developed by certified exercise physiologists, which will be integrated and coordinated with community-based exercise facilities. We plan to evaluate, using a randomized control group comparison design, the relative effectiveness of the proposed interventions in reducing conversion to NIDDM in persons with IGT, and deterioration of glucose tolerance in newly diagnosed NIDDMs as primary end points and macrovascular risk factors, coronary events, and overall mortality as secondary end points. In summary, the prevalence of diabetes mellitus is increasing at an alarming rate in the U.S., especially among minority populations. Individuals with IGT and prior GDM, who are at substantial diabetes and cardiovascular risk, can be easily identified. Furthermore, methods are currently available for potentially reducing insulin resistance and improving glucose tolerance. Thus, it is appropriate and essential to initiate a multi-center, collaborative study of interventions designed to address the stated goals. In the current proposal, we define an approach which is applicable to a multi-center trial and based on many of the strengths and resources available at Indiana University.